Safety control and signal system for motor vehicles



Nov. 16, 1954 H. T. HIGGiNS Re. 23,395

SAFETY CONTROL AND SIGNAL SYSTEM FOR MOTOR VEHICLES Original Filed Dec.22, 1948 12201922302 Haflold United States Patent Office Re. 23,895Reissued'Nov. 16, 1954 SAFETY CONTROL AND SIGNALSYSTEM FOR MOTORVEHICLES original patent but forms no part of this reissuespecificltion; matterprlnted in -italics indicates the additions madehyreissue.

My present invention relates to control means for motorvehiclestoprevent their normal operation when someunsafe conditionexists.

While my invention is adapted for other uses, its novel featuresandadvantages'may be most readily appreciated by considering its 'use inbuses. Many accidents involving buses are attributable to their havingbeen operated when some standard of safety has not been met. Forexample, it is obviously. not safe to operate a bus when the brakeoperating pressure is below apredetermined minimum but,in spite ofgauges which register suchpressure, failure of the brake system is acommoncause of accidents. While such failure is some times due 'tomechanical difficulties, it is more often due to the fact that theqrcratordoes-not take the trouble "to look atthezpressuregaugeat regularintervals or take the time to ensure that :the' engine develops adequatebrake operating pressure before the start of a trip.

In its simplest form, m invention provides control means .for a motorvehicle" III which signals, either visual or audible orboth'; areelectrically operated when one or.

more standards of safetyare not met. In practice, the

operation-of suchsignals is attended by'an interruption ofthe ignitioncircuit=and=-means are provided to enable that circuit *to be completedonly under emergency conditions. -In.its 'preferred'embodiment, myinvention also makes it. impossible-to drive the motor vehicle underemergency conditions except at a slow speed.

While such control means are well adapted to meet thegeneral objectiveof my invention of safeguarding a motor vehicle against normaloperation, either by way /of the soundingiof a signal, by interruptionof its ig- 'nitioncircuit, or by limiting its speed, when an unsafecondition exists, my -invention embodies further safcguardsasinitspreferred-embodiment, my control means meets the generalobjective of safeguards against its own failure. These are'effected byproviding that any failure in 'my control results in its being'operativeonly on the safe sideand contributingtothat is the fact that the.control relays arethelast'element intheir circuits ensuring againstimproper operationin the'event of "shorts" therein.

In thedrawing, [have indicated schematically a wiring diagram ofpreferred control means in accordance with my invention by which a motorvehicle cannot be operated, except underemergency conditions, unlesscertain standardsof safety exist.

At Ill-and '1'1, I'have indicated a battery and generator,respectively,.as the conventional source of electrical energy ofa motorvehicle. A lead 12 fromthat source includes the ignition switch13adiacent the instrument panel ld. At 15,] have indicated-a horn asillustrative of conventional warning signals and at 16 I have suggested:the ignition coil as representative of engine circuits.

At 17, I=have*indicated aprimary circuit having a first parallel-lead18- which includes the born 15, a second parallellead' lmand athirdparallel lead'20. First and second switches 21 and-22, respectively,have first and second positions. Their first positions are normaland.

as shown inthe'first position'of the switch 21, the horn circuit "isconnected 'toithe primary circuit 17 and in .theflrstposition oftheswitch 22, the second k d 19 is I the connected thereto. In their secondpositions, the switch 21 disconnects the horn circuit 18 from theprimary circuit 17 and connects the third lead 20 thereto and the switch22 opens the second lead 19.

A switch 23 has a first or normal position and a second position inwhich it connects the second lead 19 to the circuit 24 which includesthe ignition coil 16. An auxiliary power circuit 25 includesa switch 26having a normal or first position and a second position, in the first ofwhich it connects the auxiliary power circuit 25 to the second lead 19of-the-primary circuit 17.

In order'to enable the ignition circuit.24 to be closed when certainsafety'standards have not been satisfied, I provide a first controlcircuit. 27 which includes a relay 28 operatively connected-tothe switch23 so that whenever the relay 28 is energiaedthe second position'of theswitch 23 is established. I utilize a control switch 29 having a normalposition connecting the auxiliary circuit 25 to the source of electricalenergy but resiliently yieldable to connect'the control circuit 27thereto. As long as it is thus held by the :operator, the primarycircuit l7 and the ignition circuit 24 are interconnected so that theengine can be started but with the horn circuit 18 closed to therebyprovide a basis for operating the motor vehicle under emergencyconditions.

In the embodiment of .my invention shown in the drawing, I employ a leadto the source. The lead 30 includes parallel safety circuitsll and 32which have switches that are closed when certain safetyrequirements orstandards are met.

At 33, I have shown an emer indicated as having a switch 34 m the safetycircuit 31 which includes a relay 35. The switch 34 is closed when thebrake 33 is applied and the relay 35 is operatively connected to theswitches 21 and 22' to move themfrom their first or normal positionsinto their'second positions whenever it is energized. As stated,'th'eswitch 2l then connects the thirdlead20 to the primary'circuit 17 andopens the signal circuit. 18 andtheswitch 22 opens the second lead 19.The third lead 20 includes a switch 36 having a first ornormalpositionand a second position. In its first position. the switch36 connects a holding circuit 37 to the third lead 20. The holdingcircuit 37 includes a switch 38, the lead27, and the relay 28. Theswitch 38 is operatively connected to the relay 28 to be closed wheneverit is" energized.

From the foregoing, it will be apparent that when the first safetycircuit is closed, the relay 28 is energized but the primary circuit 17is disconnected from the ignition circuit 24 so thatthe auxiliarycircuit 25 must be used making it necessary for the control switch 29 tobe released into its normal position.

I have generally iudicated a device 39 responsive to brake operatingpressure and operatively connected to the normally open switch 40toclose it when a predetermined brake operating pressure exists. Untilthen, the vehicle may be driven only under emergency conditions toa safeplace or to a place where it may be given necessary service when theemergency or parking .brake 33 is released.

The device 39 may be of the type shown inmy copending application,Serial No. 578.532, filed February 17, 1945, now Patent No. 2,459,938,to prevent the. normal opening of the throttle value unlesspredetermined brake operating pressures exist sothat while the enginemay be run to warm it upor to build up brake operating pressures, itmaybe. driven only. at a slow speed under emergency conditions. 2 7

When suflicient brake operatingpressure exists to enable the motorvehicle tobe safely operated, the: device 39 is operable to close theswitch 40, thereby closing the safety circuit 32 to its relay 41. Theparking'brake 33 may then be released and the motor vehicleconventionally operated. The relay-4l is operatively connected to theswitch 26 and to the switch so that whenever it is energized, theswitches 261M136 are moved into their second positions.

In the embodiment of my invention shown in the drawings, the secondpositionofthe' switch 36 disconnects the holding circuit 37 from theprimary. circuit 17 so that switches 38 and 23are-restored'to-thetrflrst positions ncy or parking brake ignitioncircuit 24.

latches or the like.

but completes the ignition circuit 24 through the lead 42. In the secondposition of the switch 26, the auxiliary circuit 25 is disconnected fromthe second lead 19 and is connected to a holding circuit 43 for thesecond relay 3S.

, As long as suitable brake operating pressures exist, the

brake 33 may be released, but should it be released when insufiicientbrake operating pressure exists, the relay is de-energized so that theswitch 21 completes the signal circuit 18. i i I From the foregoing, itwill be appreciated that the circuit 27 includes the relay 28 and thatthis circuit may be energized, to permit emergency operation of thevehicle, by moving the switch 29 from its normal position.

When the relay 28 is energized, the switch 38 is moved relay 41. As aconsequence, the switch 26 connects the lead 27 to the lead 43 to serveas a holding circuit for the relay 35; Under these circumstances, theenergized lead 20 is connected to the lead 42 by the switch 36 which isnow in its second position and the holding circuit for the relay 28 isnow open so that its switch 23 returns to its first or normal positionto connect the lead 42 to the Various other safety factors may beprovided in accordance with my invention. Thus, I have shown the safetycircuit 32 as having a lead 44 to a pilot light 45 on the instrumentpanel 14 and as having a safety switch 46 held closed under glass as at47, by emergency door Such safety switches may be located any place inthe vehicle to provide maximum safety.

From the foregoing, it will be appreciated that under normal conditionsand with no safety standard satisfied,

the signal circuit is closed and the circuit to the ignition system isopen. Under emergency conditions, the switch may be operated by manuallyholding the switch 29 to connect the first control circuit to energizethe relay 28 to complete the circuit to the ignition system with thesignal still in operation.

When a safety standard is satisfied, such as the application of theparking brake, the relay 35 is energized and is operative to disconnectthe signal and also to connect the holding circuit to the relay 28thereby to maintain the circuit closed to the ignition system with theswitch 29 released.

While it will be apparent that my invention makes it possible tosafeguard against the operation of a motor vehicle under conditions whenit is unsafe to do so, attention is directed to the fact that in thepreferred embodiments thereof, failure of any circuit results in mycontrol means becoming operative to permit the motor vehicle to beoperated only under emergency conditions. In this connection, it will benoted that preferably each relay is the last element in its circuits sothat in the event of a short therein, normal operation of the motorvehicle when, in fact, unsafe conditions exist, is impossible. What Itherefore claim and desire to secure by Letters Patent is:

1. Control means for a motor vehicle having a switch controlled sourceof electrical energy, an electrically operated signal, and an ignitionsystem, said means comprising a primary circuit including first, second,and third parallel leads, the first of which includes said signal, firstand second switches having normal first positions in which said firstswitch connects said first lead to saidprimary circuit and said secondswitch connects said second lead thereto and second positions in whichsaid first switch disconnects said first lead from said primary circuitand connects said third lead thereto and said second switch opens saidsecond lead, a third switch having firstand second positions in thesecond of which said second lead is connected to said ignition system,an auxiliary power circuit including a fourth switch having first andsecond positions in the first of which it is connected to said secondlead, a first control circuit including a first relay operativelyconnected to said third switch to move'it from its first to its secondposition, it GZQK L 'Ql .4 switch normally connecting said auxiliarypower circuit to said source, but resiliently yieldable to connect saidfirst control circuit thereto, thereby to energize said first relay toeffect the second position of said third switch and a lead from saidsource and including first and second parallel safety circuits each ofwhich includes a switch closed in response to the existence of apredetermined standard of safety, said first safety circuit including asecond relay operatively connected to said first and second switches tomove them from their first to their second positions, said third lead ofsaid primary circuit including a fifth switch having first and secondpositions, a holding circuit connected to said first control circuit-tosaid first relay connected to' said'third lead by said fifth switch inits first position andincluding a sixth switch closed when said firstrelay is energized, said holding circuit being operable when said firstrelay is energized by the actuation of said resilient switch and whenthe safety standard of said first safety circuit is satisfied, a leadconnecting said third lead to said second ignition system when saidfifth switch is in its second position and said third switch is in itsfirst position,.and said second safety cir cuit including a third relayoperatively connected to said fourth and fifth switches to move themfrom said first to said second positions, and a holding circuit for saidsecond relay connected to said auxiliary power circuit by said fourthswitch in its second position.

2. The control means of claim 1 in which each relay is located at theground end of any circuit thereto.

3. The control means of claim 1 in which each relay operated switchreturns to its first position when its relay is de-energized.

4. The control means of claim 1 in which a safety circuit includes anormally open switch held closed when a safety standard is met.

5. Control means for a motor vehicle having a switch controlled sourceof electrical energy, an electrically operated signal, andan ignitionsystem, said control means comprising power and control circuits,separate switches in said circuits, and electrically 0 rated means, onein each control circuit to actuate said] the associated t switches froma normal position into a second position,

the normal position of said switches being such as to close a powercircuit to said signal and to open it to said system, one controlcircuit, when closed, positioning said switches to close a power circuitto said system and open it to said signal, means responsive to theexistence of a predetermined standard of safety to close that controlcircuit, another control circuit, when closed, positioning said switchesto close a power circuit to [said signal and] said system, and manuallyoperated means to close the last named control circuit.

6. Control means for a motor vehicle having a switch controlled sourceof electrical energy, an electrically operated signal, and an ignitionsystem, said control means comprising power and control circuits,separate switches in said circuits, and electrically o erated means, onein each control circuit to actuate [said the associated switches from anormal position into a second position and being located at the groundend thereof, the normal position of said switches being such as to closea power circuit to said signal and to open it to said system, onecontrol circuit, when closed, positioning said switches to close a powercircuit to said system and open it to said signal, means responsive tothe existence of a predetermined standard of safety to close thatcontrol circuit, another control circuit, when closed, positioning saidswitches to close a power circuit to [said signal and] said system, andmanually operated means to close the last named control circuit.

7. Control means for a motor vehicle having a switch controlled sourceof electrical energy, an electrically operated signal, and an ignitionsystem, said control means comprising power, control and holdingcircuits, separate switches in said circuits, and electrically o eratedmeans, one in each control circuit to actuate t e associated switchesfrom a normal position into a second position, the normal position ofsaid switches being such as to close a power circuit to said signal andto open it to said system, one control circuit, when closed, positioningsaid switches to close a power circuit to said system,

manually operated means to close said control circuit,

another control circuit,-when closed, positioning said switches todisconnect said signal from said source,,means 'of safety to close thelast named control circuit, and the holding circuit including theelectrically operated means of the first mentioned control circuit andhaving its switches arranged in series and closed one by'eachelectrically operated means when both control circuits are closed thusto enable the signal to be maintained inoperative as long as saidstandard of safety is satisfied.

8. Control means for a motor vehicle having a switch controlled sourceof electrical energy, an electrically operated signal, and an ignitionsystem, said control means comprising power, control andholding'circuits,

separate switches in said circuits, and electrically operated means, onein each control circuit to actuate the associated switches from a normalposition into a second position, thenormal position of said switchesbeing such as to close a power circuit to said signal and to open it tosaid system, one control circuit, when closed, positioning said switchesto close a power circuit to said system, manually operated means toclose said control circuit,

another control circuit, when closed, positioning said 20 2391-610switches to disconnect said signal from said source, means responsive tothe existence of a predetermined standard of safety to close the lastnamed control circuit, and the holding circuit including theelectrically operated means of the first mentioned control circuit andhaving its switches arranged in series and closed one by eachelectrically operated means when both control circuits are closed thusto enable the signal to be maintained inoperative as long as saidstandard of safety is satisfied, said electrically operated means beinglocated at the ground end of said control circuits.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS Number Name Date 872,039 Adams Nov. 26, 19071,720,230 Murray July 9, 1929 2,251,735 Goleby Aug. 5, 1941 Crane Aug.4, 1942

